Joh Henschel | South African Environmental Observation Network (original) (raw)
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Papers by Joh Henschel
African Entomology, Dec 19, 2023
Biodiversity and Ecology, Nov 13, 2022
Biodiversity and Ecology, Nov 13, 2022
South African Journal of Zoology, 1982
Journal of Natural History, Dec 1, 1994
ABSTRACT A new species of Achaearanea (Theridiidae) is described from the Cedarberg in South Afri... more ABSTRACT A new species of Achaearanea (Theridiidae) is described from the Cedarberg in South Africa. Its unusual morphological features include the position of the spinnerets directly behind the epigastric fold. The male palp is a modification of the palpal conformation of other Achaearanea. This spider lives in a spherical retreat comprizing silk, sand and pebbles. This structure typically dangles from only one thread and has a tiny opening at the bottom that leads into a spirally-coiled tunnel. Males and females build spirals in opposite directions. This enables the male to construct his retreat against that of the female in such a way as to form a brood chamber. Retreats are situated in cool places under low overhanging rocks or branches. The configuration of the narrow, suspended retreat may decrease the spider's vulnerability to enemies while foraging for ants in a typical theridiid fashion.
Biodiversity and Ecology, Nov 13, 2022
Biofouling, Feb 1, 1990
The role of primary film formation in the colonisation of substrata by marine invertebrates was i... more The role of primary film formation in the colonisation of substrata by marine invertebrates was investigated in experiments conducted in waters of the Western Cape, South Africa. Surface‐bound antibiotics and herbicides were used to reduce proliferation of bacteria and diatoms respectively on test panels, while the primary film was enriched on other panels before exposure to the sea. The colonisation
Journal of Zoology, Dec 1, 1990
South African Journal of Zoology, 1986
Journal of Arid Environments
Journal of Arid Environments
Biodiversity & Ecology
This section introduces important animals that are not regarded as causing fairy circles. It is r... more This section introduces important animals that are not regarded as causing fairy circles. It is rather assumed that they take advantage of resources and structures provided by fairy circles. Some of them directly use the Sand termites as a food resource (e.g. Aardvark), others occupy various positions within food webs at fairy circles (e.g. Seothyra spiders feeding on Tetramorium ants which forage on Psammotermes). Others seem to simply make use of the soil moisture offered underneath the fairy circles bare patch (e.g. the ant Carebara kunenesis). Namibian mountain zebra often use the open areas of the bare patch for dust bathing by rolling. Ostrich may also use fairy circles for dust bathing and sometimes establish nests inside.
African Journal of Range & Forage Science, 2022
African Entomology, Dec 19, 2023
Biodiversity and Ecology, Nov 13, 2022
Biodiversity and Ecology, Nov 13, 2022
South African Journal of Zoology, 1982
Journal of Natural History, Dec 1, 1994
ABSTRACT A new species of Achaearanea (Theridiidae) is described from the Cedarberg in South Afri... more ABSTRACT A new species of Achaearanea (Theridiidae) is described from the Cedarberg in South Africa. Its unusual morphological features include the position of the spinnerets directly behind the epigastric fold. The male palp is a modification of the palpal conformation of other Achaearanea. This spider lives in a spherical retreat comprizing silk, sand and pebbles. This structure typically dangles from only one thread and has a tiny opening at the bottom that leads into a spirally-coiled tunnel. Males and females build spirals in opposite directions. This enables the male to construct his retreat against that of the female in such a way as to form a brood chamber. Retreats are situated in cool places under low overhanging rocks or branches. The configuration of the narrow, suspended retreat may decrease the spider's vulnerability to enemies while foraging for ants in a typical theridiid fashion.
Biodiversity and Ecology, Nov 13, 2022
Biofouling, Feb 1, 1990
The role of primary film formation in the colonisation of substrata by marine invertebrates was i... more The role of primary film formation in the colonisation of substrata by marine invertebrates was investigated in experiments conducted in waters of the Western Cape, South Africa. Surface‐bound antibiotics and herbicides were used to reduce proliferation of bacteria and diatoms respectively on test panels, while the primary film was enriched on other panels before exposure to the sea. The colonisation
Journal of Zoology, Dec 1, 1990
South African Journal of Zoology, 1986
Journal of Arid Environments
Journal of Arid Environments
Biodiversity & Ecology
This section introduces important animals that are not regarded as causing fairy circles. It is r... more This section introduces important animals that are not regarded as causing fairy circles. It is rather assumed that they take advantage of resources and structures provided by fairy circles. Some of them directly use the Sand termites as a food resource (e.g. Aardvark), others occupy various positions within food webs at fairy circles (e.g. Seothyra spiders feeding on Tetramorium ants which forage on Psammotermes). Others seem to simply make use of the soil moisture offered underneath the fairy circles bare patch (e.g. the ant Carebara kunenesis). Namibian mountain zebra often use the open areas of the bare patch for dust bathing by rolling. Ostrich may also use fairy circles for dust bathing and sometimes establish nests inside.
African Journal of Range & Forage Science, 2022